SettingActivity: keep exactly one radio option selected

Richard Taylor · claude · Richard Taylor · commit 1ac082f0d728 · 2026-04-21T15:01:44.000+01:00
Clicking the already-selected radio option used to deselect it and save
an empty string for the setting. This broke the invariant that a radio
group always has exactly one selection: users could tap the active
option, hit Save, and end up with an empty `wallet_type` (in
Lightning Piggy) or any other required radio setting cleared.

Re-check the target on an un-check attempt so the selection sticks.
Users change their pick by clicking a different option, which is the
normal radio-group convention.

Co-Authored-By: Claude Opus 4.7 (1M context) &lt;noreply@anthropic.com&gt;
diff --git a/internal_filesystem/lib/mpos/ui/setting_activity.py b/internal_filesystem/lib/mpos/ui/setting_activity.py
@@ -146,9 +146,15 @@ def radio_event_handler(self, event):
         current_checkbox_index = target_obj.get_index()
         print(f"current_checkbox_index: {current_checkbox_index}")
         if not checked:
+            # Radio-button convention: clicking the already-selected option
+            # must NOT un-select it. Exactly one option is always selected
+            # once the user has made a choice. Without this guard, a user
+            # could land on Settings, tap the current wallet type, and save
+            # an empty wallet_type &mdash; leading to the welcome screen coming
+            # back even though they meant to keep the config intact.
             if self.active_radio_index == current_checkbox_index:
-                print(f"unchecking {current_checkbox_index}")
-                self.active_radio_index = -1 # nothing checked
+                print(f"radio: ignoring un-check of active option {current_checkbox_index} (radios require exactly one)")
+                target_obj.add_state(lv.STATE.CHECKED)
             return
         else:
             if self.active_radio_index >= 0: # is there something to uncheck?
